I'm just thinking of all those long hours researching, designing, buying parts for and assembling only for it become practically useless soon after.
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Anyone have some words of wisdom to share?
The Journey is the Destination. 
Seriously -- for me, the "long hours researching, designing, buying parts for and assembling" is where a lot of the value lies in these hobby projects. I am learning new things, sometimes get surprising and delightful insights, and in the end have this happy "look what I've built!" moment.
I have long since realized that I enjoy the process of learning, designing and building much more than actually using the resulting device; whether that's a ham radio transmitter, vintage computer replica or vintage game, whatever. And I am happy with that state of affairs!
I do tend to hang on to the finished (or sometimes not-quite-finished) gadgets I have built. Maybe that's a bad habit, but I do enjoy looking at the stuff every now and then, thinking back to the journey of having figured things out -- certainly without any guilty feelings that I don't use the resulting gizmos much!
